Colonel William Hawley (1861-1941) was a British archaeologist who most famously undertook pioneering excavations at Stonehenge.

The work was carried out between 1919 and 1926 largely by Hawley working alone although at other times assisted by Robert Newall and a draughtsman from the Office of Works to record his work. The weather and the confusing stratigraphy of this site made work difficult but Hawley was able to make numerous breakthroughs regarding the history of activity on the site.

The work was initially focused on the supervised righting of some of the fallen stones late in 1919. Hawley dug out the foundations before the stones were replaced. Hawley was employed by the Office of Works, the antecedent of the Ministry of Works who had been passed responsibility for Stonehenge when it had been donated to the nation in 1918. They were primarily concerned with the danger of falling stones but funds were made available for Hawley to continue his investigations long after the righting work finished.

Hawley's work identified the Aubrey Holes for the first time as well as the Y and Z holes and a jumble of other postholes and stone holes within the centre of the monument. He found many of the cremated and uncremated human remains which first indicated a funerary role for Stonehenge. Excavation of the Avenue and the ditch around the Heelstone was also undertaken.

Hawley proved, from a thin stratum of stone chip debris he called the Stonehenge Layer, that the earthwork features, the Aubrey Holes and some of the other postholes and burials constituted earlier phases of activity that predated the erection of the megaliths. He also found an antler pick embedded in a lump of chalk indicating the construction method on site. Eventually he settled on three phases, the earthwork enclosure, a large stone circle now vanished that supposedly stood in the Aubrey Holes, and finally a larger megaliths phase involving the extant stones as Stonehenge 3. Hawley's model of a multiphase site did not agree with the contemporary interpretation and was ignored until Richard Atkinson revived the idea in the 1950s. Although now considerably refined, his multiphase interpretation is now fully accepted.

Certain of Hawley's other ideas such as Stonehenge being a fortified settlement were further off the mark and he died before his work was recognised.